How To Backup Your Computer

Losing your photos, documents, and personal files can be devastating. A computer backup creates a safe, second copy of your important data, protecting you from hard drive failure, theft, malware, or simple accidents. This guide walks you through the entire process, whether you're using a Windows PC or a Mac, and explains the best methods to keep your digital life secure. We'll cover using both external hard drives and cloud services, ensuring you can choose the right option for your needs and budget.

Fast Answer

Windows (10/11): Use the built-in 'File History' feature with an external hard drive.
macOS: Use the built-in 'Time Machine' feature with an external hard drive.
Universal Method: Sign up for a cloud backup service that automatically saves your files online.

30 mins - 8+ hours Time needed

Easy Difficulty

Unverified backups Watch out for

Before You Start

A backup destination: This will either be an external hard drive (HDD or SSD) or a subscription to a cloud backup service.
Sufficient storage space: Your backup destination should have at least as much free space as the data you're backing up. We recommend a drive that is at least twice the size of your computer's internal storage to allow for future growth and multiple backup versions.
A stable power connection: Plug your laptop into the mains before starting your first backup. A power cut midway through a large backup can cause issues.
A reliable internet connection: This is only necessary if you choose a cloud backup method. A faster connection will significantly speed up the process.

Check first: If using a new external drive, it may need to be formatted for your computer (Windows uses NTFS, macOS uses APFS). Be aware that setting up a drive for backups often involves erasing all existing data on it. Do not use a drive that contains other important files unless you have copied them elsewhere first.

Step-by-Step Instructions

Choose Your Backup Method

You have two main choices for backing up your computer: a local backup to an external drive or a remote backup to a cloud service. Understanding the pros and cons of each is the first critical step.

Local Backup (External Hard Drive): This involves buying a physical hard drive and connecting it to your computer. It's a popular choice because it's fast and has a one-time cost. You have complete physical control over your data. However, your backup is vulnerable to the same local disasters as your computer, like fire, flood, or theft. You must remember to connect the drive regularly for the backup to run.

Cloud Backup (Online Service): This method involves paying a monthly or yearly subscription to a company that automatically backs up your files over the internet to their secure servers. The main advantage is that your data is stored off-site, protecting it from local disasters. It's a true "set it and forget it" solution. The downsides are the recurring cost, the initial backup can be very slow depending on your internet speed, and you are trusting a third party with your data.

Tip: For the best protection, security experts recommend the 3-2-1 rule: have at least 3 total copies of your data, on 2 different types of media, with 1 copy stored off-site. A common setup is your computer (copy 1), an external hard drive (copy 2, different media), and a cloud backup (copy 3, off-site).

How to Backup a Windows PC with File History

For most users on Windows 10 and Windows 11, the easiest built-in tool is File History. It automatically backs up versions of your files in the main user folders (Desktop, Documents, Downloads, Music, Pictures, Videos).

Connect your external drive: Plug your external hard drive into a USB port on your computer.
Open Backup settings: Click the Start menu, type "Backup settings", and press Enter. This will open the correct page in the Settings app.
Add the drive: Under the "Back up using File History" section, click on "Add a drive". Windows will search for suitable drives and display your connected external drive. Select it from the list.
Enable automatic backups: Once you select the drive, File History will automatically be turned on. A new switch labelled "Automatically back up my files" will appear and be toggled on.
Customise your backup (optional): Click on "More options" below the on/off toggle. Here you can change how often File History saves copies of your files (from every 10 minutes to daily), how long it keeps saved versions, and add or remove specific folders from the backup plan. By default, it covers the most important user folders, which is perfect for most people.

File History will now quietly work in the background, creating copies of your files on the external drive whenever it's connected. The first backup will take the longest, while subsequent backups will be much faster as it only copies new or changed files.

How to Backup a Mac with Time Machine

Time Machine is Apple's excellent, user-friendly backup software that is built into every Mac. It creates a complete backup of your computer, including your personal files, apps, and the operating system itself.

Connect your external drive: Plug your external drive into your Mac.
Confirm use as a backup disk: macOS is smart. It will likely detect the new drive and show a pop-up dialogue box asking if you want to use it to back up with Time Machine. If it does, simply click "Use as Backup Disk". You may be prompted to encrypt the backup, which is highly recommended for security.
Set it up manually (if no prompt appears): If the pop-up doesn't show, go to the Apple menu > System Settings. Then click General in the sidebar, and click Time Machine on the right.
Add your backup disk: Click the "Add Backup Disk" button (or the '+' button). Select your connected external drive from the list and click "Set Up Disk". You will be asked if you want to erase the drive to prepare it for Time Machine; click "Erase". This is why using a dedicated, empty drive is so important.
Let it run: Time Machine will now begin your first backup automatically. This initial backup can take several hours depending on how much data you have. Once it's complete, Time Machine will automatically back up any changes hourly, as long as the drive is connected.

You can check the status of your backup by clicking the Time Machine icon in the menu bar at the top of your screen. It looks like a clock with a counter-clockwise arrow.

Using a Third-Party Cloud Backup Service

If you've opted for a cloud backup solution, the process is broadly similar regardless of the provider you choose. These services are designed to be as simple as possible.

Choose a service and create an account: Research and select a reputable cloud backup provider. Sign up for a plan that offers enough storage for your needs.
Download and install the software: From the provider's website, download their desktop application for your operating system (Windows or macOS) and install it just like any other program.
Sign in and configure: Launch the application and sign in with the account you just created. The setup wizard will guide you through the process. It will usually ask what you want to back up. Most services default to backing up your main user folders, which is a good starting point. Some allow for a full computer backup.
Start the initial backup: Once configured, the software will begin scanning your files and uploading them to the cloud. This is the most time-consuming part. The initial upload can take anywhere from a few hours to several weeks, depending on the amount of data and your internet upload speed. It's best to let this run continuously in the background.

Tip: For the very first cloud backup, connect your computer to your router with an Ethernet cable if possible. A wired connection is almost always faster and more stable than Wi-Fi, which can speed up this long initial process.

Verify Your Backup Is Working

A backup is useless if you can't restore data from it. Never assume your backup is working correctly without checking. This simple verification step provides peace of mind that your data is truly safe.

For External Drive Backups (File History/Time Machine):

Open your backup drive from File Explorer (Windows) or Finder (Mac).
Navigate through the folder structure to find a non-critical document or photo.
Try to open the file directly from the backup drive. If it opens correctly, your backup is likely working.
For a more thorough test, copy that file from the backup drive to your desktop and open it from there. This mimics a real restoration process.

For Cloud Backup Services:

Log in to your account on the backup provider's website.
Use their web interface to browse your backed-up files.
Find a specific file and use the 'Download' or 'Restore' option to save a copy to your computer.
Open the downloaded file to ensure it's not corrupted and is the correct version.

Performing this simple check once after your first backup, and then periodically every few months, is one of the most important parts of a reliable backup strategy.

Quick Reference

Situation	Use this	Why
I want the simplest, most affordable method.	External Hard Drive	It's a one-time purchase with no recurring fees. Built-in tools like Time Machine and File History make it very easy.
I want maximum protection against theft, fire, or flood.	Cloud Backup Service	Your data is stored securely off-site, so it's safe even if something happens to your home and computer.
I need to access my backed-up files from anywhere.	Cloud Backup Service	You can log in from any computer or phone to access and download your backed-up files.
I have a slow or data-capped internet connection.	External Hard Drive	Backups and restores are much faster as they don't depend on the internet and won't use up your data allowance.
I want a completely automated 'set and forget' solution.	Cloud Backup Service	It works automatically in the background whenever you're connected to the internet, without needing to plug in a drive.

Common Problems When You Backup Your Computer

The backup is taking forever.	The first backup is always the longest. For local backups, ensure you're using a modern drive with a fast connection (USB 3.0 or higher). For cloud backups, a slow internet upload speed is the usual culprit. Let the initial backup run overnight or over a weekend. Subsequent backups will be much faster.
My backup drive is out of space.	This is a common issue. The best solution is to buy a larger drive. Alternatively, you can go into your backup settings and exclude large folders that you don't need to protect, such as your 'Downloads' folder or folders containing temporary application files. Both File History and Time Machine allow you to exclude specific folders.
The backup failed with an error message.	First, try the simple things: unplug the drive and plug it back in, then restart your computer. If the problem persists, the drive itself may have issues. Use your computer's built-in tools (Disk Utility on Mac, Error Checking on Windows) to scan the external drive for problems.
I don't know the difference between a backup and cloud sync.	This is a critical distinction. Sync services like Dropbox, Google Drive, and OneDrive are designed for file access and collaboration. They mirror your files. If you accidentally delete a file from your computer, it will also be deleted from the sync service. A true backup service creates a separate, safe archive. If you delete a file from your computer, you can still go into your backup and restore it.

Advanced Tips for how to backup your computer

Encrypt Your Backups	If your external hard drive is ever lost or stolen, an unencrypted backup gives a thief access to all your personal data. When you set up Time Machine or File History, look for an option to encrypt the backup. This will require a password to restore files, making your data unreadable to anyone else. It's a vital security step.
Create a Full System Image	File History and basic Time Machine backups are great for your personal files. A 'system image', however, is a complete snapshot of your entire hard drive, including Windows or macOS, your settings, programs, and all files. If your main drive fails completely, you can use this image to restore your computer to the exact state it was in when the backup was made. Windows has a built-in tool for this (often called "Backup and Restore (Windows 7)") and Time Machine's recovery mode functions in a similar way.
Keep Multiple Backup Drives	For extra security, consider using two external drives. You could keep one connected for daily backups, and another that you only connect once a month and then store at a different location, like your office or a relative's house. This gives you an off-site backup without paying for a cloud subscription.

How To Backup Your Computer FAQ

How often should I back up my computer?

The best answer is "as often as possible". Luckily, modern tools like Time Machine and File History make this easy by running automatically. They are typically set to back up hourly or daily. For most people, letting the software run on its default automatic schedule is the perfect approach.

What size external hard drive do I need?

A good rule of thumb is to buy a drive that is at least double the capacity of your computer's internal storage. For example, if your laptop has a 512GB hard drive, get at least a 1TB external drive. This provides ample space for the full initial backup, plus room for future files and multiple older versions of your files.

How long do external drives last?

Mechanical hard disk drives (HDDs) typically have a lifespan of 3 to 5 years before the risk of failure increases significantly. Solid-state drives (SSDs) don't have moving parts and can last longer, but they do have a finite number of writes. It's a good practice to plan on replacing your primary backup drive every 4-5 years to be safe.

Can I use my backup drive to store other files too?

It is strongly recommended that you use a drive exclusively for backups. Mixing backups with general storage can complicate the process, lead to the drive filling up unexpectedly, and increases the risk of you accidentally deleting important backup data. Dedicate one drive solely for this critical task.

Final Checklist for how to backup your computer

You have decided between a local external drive and a remote cloud service.
You have an external drive or cloud plan with enough storage space (ideally 2x your computer's storage).
You have configured your chosen software (File History, Time Machine, or a third-party app).
You have run the first full backup of your computer.
You have confirmed that automatic, scheduled backups are enabled.
You have tested the backup by successfully finding and restoring at least one file.
Your external backup drive is stored in a safe, dry place when not in use.